1. Technical Field
Exemplary embodiments of the present invention relate to a resistive memory device and method of manufacturing the same, and more particularly, to a schottky diode capable of ensuring ON and OFF current characteristics, a resistive memory device having the schottky diode, and a method of manufacturing the same.
2. Related Art
Generally, resistive memory devices such as phase-change memory devices use a switching device to selectively apply a voltage or current to a resistive medium. Vertical type diodes having a relatively small unit area have been used as the switching device.
With exponential increase in integration density of semiconductor memory devices, a critical dimension (CD) of the switching device is reduced below exposure limits. However, when the CD and area of the switching device are reduced, a contact area between the switching device and a word line is reduced and thus ON current of a memory cell is reduced.
In order to overcome reduction in the ON current, schottky diodes having a low threshold voltage have been used instead of conventional PN diodes.
The schottky diodes are formed by depositing a polysilicon layer on a metal word line and ion implanting impurities such as boron (B) into the polysilicon layer.
Such a schottky diode has a superior ON current characteristic to conventional PN diodes. However, boron penetration is caused during a process of diffusing the impurities such B and thus OFF current characteristics of a memory cell are degraded.